Job 1:3

His possessions were seven thousand sheep, three thousand camels, five hundred yoke of oxen, five hundred female donkeys, and very many servants. This man was the greatest of all the people of the East.
Job 1:3, Modern English version (MEV)
 
From Albert Barnes’ Notes on the whole Bible:
 
His substance - Margin, or “cattle.” The word used here מקנה mı̂qneh is derived from קנה qânâh, to gain or acquire, to buy or purchase, and properly means anything acquired or purchased - property, possessions, riches. The wealth of nomadic tribes, however, consisted mostly in flocks and herds, and hence the word in the Scripture signifies, almost exclusively, property in cattle. The word, says Gesenius, is used “strictly” to denote sheep, goats, and neat cattle, excluding beasts of burden (compare Greek κτῆνος ktēnos, herd, used here by the Septuagint), though sometimes the word includes asses and camels, as in this place.
 
Seven thousand sheep - In this verse we have a description of the wealth of an Arab ruler or chief, similar to that of those who are at this day called “Emirs.” Indeed the whole description in the book is that which is applicable to the chief of a tribe. The possessions referred to in this verse would constitute no inconsiderable wealth anywhere, and particularly in the nomadic tribes of the East. Land is not mentioned as a part of this wealth; for among nomadic tribes living by pasturage, the right to the soil in fee simple is not claimed by individuals, the right of pasturage or a temporary possession being all that is needed. For the same reason, and from the fact that their circumstances require them to live in movable tents, houses are not mentioned as a part; of the wealth of this Emir. To understand this book, as well as most of the books of the Old Testament, it is necessary for us to lay aside our notions of living, and transfer ourselves in imagination to the very dissimilar customs of the East. The Chaldee has made a very singular explanation of this verse, which must be regarded as the work of fancy, but which shows the character of that version: “And his possessions were seven thousand sheep - a thousand for each of his sons; and three thousand camels - a thousand for each of his daughters; and five hundred yoke of oxen - for himself; and five hundred she-asses - for his wife.”
 
And three thousand camels - Camels are well-known beasts of burden, extensively used still in Arabia. The Arabs employed these animals anciently in war, in their caravans, and for food. They are not unfrequently called “ships of the desert,” particularly valuable in arid plains because they go many days without water. They carry from three to five hundred pounds, in proportion to the distance which they have to travel. Providence has adapted the camel with wonderful wisdom to sandy deserts, and in all ages the camel must be an invaluable possession there. The driest thistle and the barest thorn is all the food that he requires, and this he eats while advancing on his journey without stopping or causing a moment’s delay. As it is his lot to cross immense deserts where no water is found, and where no dews fall, he is endowed with the power of laying in a store of water that will suffice him for days - Bruce says for thirty days.
 
To effect this, nature has provided large reservoirs or stomachs within him, where the water is kept pure, and from which he draws at pleasure as from a fountain. No other animal is endowed with this power, and were it not for this, it would be wholly impracticable to cross those immense plains of sand. The Arabians, the Persians, and others, eat the flesh of camels, and it is served up at the best tables in the country. One of the ancient Arab poets, whose hospitality grew into a proverb, is reported to have killed yearly, in a certain month, ten camels every day for the entertainment of his friends. In regard to the hardihood of camels, and their ability to live on the coarsest fare, Burckhardt has stated a fact which may furnish an illustration. In a journey which he made from the country south of the Dead Sea to Egypt, he says, “During the whole of this journey, the camels had no other provender than the withered shrubs of the desert, my dromedary excepted, to which I gave a few handfuls of barley each evening.” Trav. in Syria, p. 451; compare Bruce’s Travels, vol. iv. p. 596; Niebuhr, Reise-beschreibung nach Arabien, 1 Band, s. 215; Sandys, p. 138; Harmer’s Obs. 4:415, ed. Lond. 1808, 8vo; and Rob. Cal.
 
And five hundred yoke of oxen - The fact that Job had so many oxen implies that he devoted himself to the cultivation of the soil as well as to keeping flocks and herds; compare Job 1:14. So large a number of oxen would constitute wealth anywhere.
 
And five hundred she-asses - Bryant remarks (Observations, p. 61) that a great part of the wealth of the inhabitants of the East often consisted of she-asses, the males being few and not held in equal estimation. She-asses are early mentioned as having been in common use to ride on; Numbers 22:25; Jdg 5:10. 2 Kings 4:24 (Hebrew). One reason why the ass was chosen in preference to the horse, was that it subsisted on so much less than that animal, there being no animal except the camel that could be so easily kept as the ass. She-asses were also regarded as the most valuable, because, in traversing the deserts of the country they would furnish travelers with milk. It is remarkable that “cows” are not mentioned expressly in this enumeration of the articles of Job’s wealth, though “butter” is referred to by him subsequently as having been abundant in his family, Job 29:6. It is possible, however, that “cows” were included as a part of the “five hundred yoke of בקר bâqâr.” here rendered “oxen;” but which would be quite as appropriately rendered “cattle.” The word is in the common gender, and is derived from בקר bâqar, in Arabic to cleave, to divide, to lay open, and hence, to plow, to cleave the soil. It denotes properly the animals used in plowing; and it is well known that cows are employed as well as oxen for this purpose in the East; see Judges 14:18; Hosea 4:10; compare Deuteronomy 32:14, where the word בקר bâqâr is used to denote a cow - “milk of kine,” Genesis 33:13 (Hebrew).
 
And a very great household - Margin, “husbandry.” The Hebrew word here (עבדה ‛ăbûddâh)ambiguous. - It may denote service rendered, that is, work, or the servants who performed it; compare Genesis 26:14, margin. The Septuagint renders it ὑπηρεσία hupēresia, Aquila δουλεία douleia, and Symmachus, οἰκετία oiketia; all denoting “service,” or “servitude,” or that which pertained to the domestic service of a family. The word refers doubtless to those who had charge of his camels, his cattle, and of his husbandry; see Job 1:15. It is not implied by the word here used, nor by that in Job 1:15, that they were “slaves.” They may have been, but there is nothing to indicate this in the narrative. The Septuagint adds to this, as if explanatory of it, “and his works were great in the land.”
 
So that this man was the greatest - Was possessed of the most wealth, and was held in the highest honor.
 
Of all the men of the East - Margin as in Hebrew “sons.” The sons of the East denote those who lived in the East. The word “East” קדם qedem is commonly employed in the Scriptures to denote the country which lies east of Palestine. For the places intended here, see the Introduction, Section 2, (3). It is of course impossible to estimate with accuracy the exact amount of the value of the property of Job. Compared with many persons in modern times, indeed, his possessions would not be regarded as constituting very great riches. The Editor of the Pictorial Bible supposes that on a fair estimate his property might be considered as worth from thirty to forty thousand pounds sterling - equivalent to some 200,000 (circa 1880’s). In this estimate the camel is reckoned as worth about 45.00 dollars, the oxen as worth about five dollars, and the sheep at a little more than one dollar, which it is said are about the average prices now in Western Asia. Prices, however, fluctuate much from one age to another; but at the present day such possessions would be regarded as constituting great wealth in Arabia. The value of the property of Job may be estimated from this fact, that he had almost half as many camels as constituted the wealth of a Persian king in more modern times.
 
Chardin says, “as the king of Persia in the year 1676 was in Mesandera, the Tartars fell upon the camels of the king and took away three thousand of them which was to him a great loss, for he had only seven thousand.” - Rosenmuller, Morgenland, “in loc.” The condition of Job we are to regard as that of a rich Arabic Emir, and his mode of life as between the nomadic pastoral life, and the settled manner of living in communities like ours. He was a princely shepherd, and yet he was devoted to the cultivation of the soil. It does not appear, however, that he claimed the right of the soil in “fee simple,” nor is his condition inconsistent with the supposition that his residence in any place was regarded as temporary, and that all his property might be easily removed. “He belonged to that condition of life which fluctuated between that of the wandering shepherd, and that of a people settled in towns. That he resided, or had a residence, in a town is obvious; but his flocks and herds evidently pastured in the deserts, between which and the town his own time was probably divided. He differed from the Hebrew patriarchs chiefly in this, that he did not so much wander about “without any certain dwelling place.”